In the art of preparing polymers, it can be desirable to impart to or increase the branching of polymer chains. Increased branching may impart physical property changes to the polymer, such as increased strength, higher temperature performance, and improved hardness, for example. In some instances, increased branching may improve properties such as elastomeric performance and abrasion resistance.
Ionomers are known to be useful in many applications. For example, a polyester ionomer dyeability enhancer may be derived from the reaction residue of an aryl carboxylic acid sulfonate salt, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, an aliphatic diol or any of their ester-forming derivatives. A photocurable dental cement may be prepared using a photocurable ionomer, which is defined as a polymer having sufficient pendent ionic groups to undergo a setting reaction in the presence of a reactive filler and water, and sufficient pendent polymerizable groups to enable the resulting mixture to be polymerized, e.g., cured upon exposure to radiant energy.
However, efforts continue to improve physical properties of polymers.